The performance and efficiency of internal combustion engines are subject to increasingly strict requirements. At the same time increasingly stringent legal provisions require pollutant emissions to be kept low. To this end it is known that internal combustion engines can be fitted with a plurality of control elements to adjust the level in the respective combustion chambers of the cylinders of the internal combustion engine, the level before combustion comprising a mixture of air, fuel and in some instances also exhaust gases. Phase adjustment facilities for example are known, which can be used to change a phase between a crankshaft and a camshaft of the internal combustion engine, thereby changing the respective start and end of the opening or closing of the gas inlet and gas outlet valves. Valve lift adjustment facilities are also known, which can be used to adjust a valve lift of the gas inlet valve or even a gas outlet valve of the internal combustion engine between a low and high valve lift.
Internal combustion engines are also regularly fitted with tank purging devices, by means of which fuel evaporation emissions from a tank in a vehicle, in which the internal combustion engine can be disposed, are buffered in an active carbon store. What is known as a tank purging valve is used at regular intervals to regenerate the active carbon store. The tank purging valve thereby releases a connection to the intake duct of the internal combustion engine. The fuel bound in the active carbon store can thus flow into the intake duct of the internal combustion engine and be combusted in the respective cylinder of the internal combustion engine. For precise operation of the internal combustion engine with low emissions, it is essential that such additionally incorporated fuel is also taken into accurate account.